Which expressions are equivalent to 2r + (t + r)2r+(t+r)2, r, plus, left parenthesis, t, plus, r, right parenthesis ? Choose all answers that apply:
Choose all answers that apply:

(Choice A)
A
2rt + 4r

(Choice B)
B
r+tr

(Choice C)
C
None of the above

9514 1404 393

  C  none of the above

Step-by-step explanation:

We can simply drop the parentheses and collect terms.

  2r +(t +r) = 2r + t + r = (2r +r) +t

  = 3r +t

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15